Load Development - Process

[rlownote]

For the experts on here - do you guys figure out what COAL your chamber likes first, and then test powder loads at that seating depth, or do you pick your powder load and then test varying seating depths to dial it in? It doesn't seem like you can work on both at the same time - or can you?

 

[spife7980]

I do a coarse powder, seating depth, refine the powder and confirm.

 

[Aftermath]

I start with bullet up against the rifling and find max charge by looking for pressure signs. Then I back off the charge some, check velocity. Then I start seating deeper and deeper. Once that gets to where I am happy with accuracy, I run another 20 or so at that charge/depth across the chrono. Usually am finished with load development in 20-40 rounds, then the extra across the chronograph.

 

[spife7980]

And mine usually take 100-150. The difference being that aftermath is fine with what he sees if it meets his standards, I want to see if I’m missing anything that may be a bit better. Usually my first impressions are correct and aftermaths method saves a trip or two. Once in a while I see that there was more to be gained with further testing, at least if you’re shooting paper.
And then there is the third party that says load development at all is a crock of shit. I call them idiots.

 

[wvfarrier]

I usually start powder testing two thousandths off the lands and see where it goes

 

[Aftermath]

And mine usually take 100-150. The difference being that aftermath is fine with what he sees if it meets his standards, I want to see if I’m missing anything that may be a bit better. Usually my first impressions are correct and aftermaths method saves a trip or two. Once in a while I see that there was more to be gained with further testing, at least if you’re shooting paper.
And then there is the third party that says load development at all is a crock of shit. I call them idiots.

This is 100% true. Especially about the idiots.

I use to go a bit farther and still do once in a while.
By that, I mean, once I have that good precision at the initial charge and seating depth, I would then try more powder at this seating depth. This may seem counter to what I said before because I had already found max charge...but when you move that bullet away from the rifling, the pressure will go down. Since I can't actually measure, I will go by what I have read and say that just a couple of thousandths makes a significant reduction in pressure...and velocity. So, I have tried pushing that back up by adding some powder. Thing is, maybe 80-90% of the time, accuracy falls off. I'd need to work on a new seating depth.

Just my opinion, maybe a little educated but 100% no proof, I think that a certain bullet (and the other variables..barrel, brass, primer, chamber) work best at a certain PRESSURE. I will leave it there.

 

[RegionRat]

Rather than just say something cute like "it depends...."... let me just throw out some food for thought...

Magazine, or single load? (Semi/Full Auto?)
Known bullet and chamber combination. or totally unknown?
Sporting carry rifle, or match gun?
Secant, tangent, or hybrid?

You see my point? I am not a good writer and it is hard to convey why the context for your question is very important. Without context, your answers will run all over the map.

Sometimes, jam is appropriate and we have a rough charge in mind based on several barrels and tribal knowledge from our fellow competitors. In that context, we start with seating depth and then cycle back and forth to charge and verify that first seating depth.

In other context, we need jump in order to eject a loaded round, so we may start with powder charge and jump 0.020", then when we find a good charge we circle back to investigate jump.

There is no single answer to this because there is no single context.

 

[tinker]

And mine usually take 100-150. The difference being that aftermath is fine with what he sees if it meets his standards, I want to see if I’m missing anything that may be a bit better. Usually my first impressions are correct and aftermaths method saves a trip or two. Once in a while I see that there was more to be gained with further testing, at least if you’re shooting paper.
And then there is the third party that says load development at all is a crock of shit. I call them idiots.

My favorite idiots are the ones who say "seating depth doesn't matter, just load to mag length". Right now for fun I am testing a bunch of diff stuff at diff seating depths and filming it to show the difference. I may share it if it doesn't end up seeming boring.

I don't worry about MAX charge. I start usually somewhere around a medium charge and if the accuracy is good I will use that charge (so long as the velocity is good, for me I am not trying to set speed records or burn out a barrel as fast as possible). Heck for my 6BR I am at 28.9 gr of varget W/ 105 gr bullets and getting 2800 fps and a little more. That is plenty fast enough for me and get 1/2 moa or better.

After I get a charge weight I am happy with I will try seating depth (I start @ .010 off the lands). Then after I find a seating depth that seems to do ok, I will load more and shoot 5 shot groups with that to confirm and after 20-30 rds if it's good I call it good. If those 20-30 didn't confirm, I try some other stuff.

I have a 6.5x47 that really doesn't like 123gr bullets for some reason but it likes 140s. I am planning on trying some more 123s at some point though because I have a few thousand of them.

 

[tinker]

Short answer though is no you can't do both at the same time. Too many variables. Do one thing at a time to make sure THAT is the thing making the difference.

But charge weight is much more important that minor changes to seating depth so charge weight def comes first IMO.